Method of making duplicate copies



Patented Feb. 14, 1939 UNITED 7 STATES METHOD OF MAKING DUPLICATE COPIESGeorge G. Neidicli,

Application February 23, 1937,

No Drawing.

New York, N. Y.

Serial No. 127,169

10 Claims.

Thisinvention relates to improvements in methods of making duplicatecopies, and more particularly to improvements in offset duplicationmethods of making'dupiicate copies of typegrkitten. matter, hand writtenmatter, and the Heretofore several methods have been employed forproducing copies of matter of the foregoing character, all of whichmethodsresuit in the production of duplicate copies of master images,which copies are usually produced on paper contacted in some manner witha master having thereon an image of the work to be duplicated, whichmaster contains material quantities of strong dyestuff adapted to betransferred to the copies in the steps followed in the differentprocesses.

-In one method, use is made of what is known to the art as a hectographpan. In this method a gelatin compound is disposed in a pan, A normalmaster sheet is typewritten, written, or drawn, with an ink stronglycolored with basic dyestufl, usually crystal violet, the master beingusually in' the form of a sheet of paper or the like. Crystal violet isordinarily used since this dyestuff is more powerful and is more quicklysoluble than other dyestuif. The master is laid on the top surface ofthe gelatin compound in the pan and permitted to remain in contact withso the surface thereof until the compound absorbs locally sufficient ofthe dyestufl to produce at least onehundred copies of the matter to bereproduced. The absorption of dyestuff from the master is in accordancewith the lines of 5 the image on the master so that in effect a mirrorreverse copy of the matter to be reproduced is formed in the compound.Sheets of copy paper are then contacted with the surface of thecompound, resulting in the transfer of suflicient dyestuff from thecompound to the copy sheets as to produce copies of the matter desired.

This principle has been further extended to a process in which thegelatin composition is thickly coated on a backing sheet, usually as a45 roll of considerable length fastened to the drum of a two cylindermachine. The same procedure for causing absorption of dyestuff isfollowed out so that the composition contains absorbed therein a mirrorreverse copy of the original in matter and the surface of the gelatinbecomes a printing medium. Copy sheets are fed between the mastercylinder (having the gelatin surface) and a platen cylinder causingtransfer of dyestuff to the copy sheets and thereby producing I. legiblecopies of'the desired matter.

' tactd with the mirror reverse copy on the master use thereof: Sincethe processes have required .-moisture of the-hands of the user alone issuiii- In still another process, use is made of a method known to theart as spirit duplication. In this process, a master. copy in strongsoluble basic anilin dyestuif is produced by typewriter, writing ordrawing, as in the case of the gelatin processes, except that thetypewriting, writing, or drawing is in mirror reverse. Ordinarily, useis made of a special carbon paper whose active surface is placed incontact with one side of the master sheet on which the originaltypewriting, writing, or drawing is imposed. When the image to bereproduced is imposed on one surface of this master sheet, the othersurface thereof, which is in contact with the carbon paper, acquires adeposit of the coating material of the carbon paper according to thelines of impress on the blank surface thereof. Thus a mirror reversecopy of the matter to be reproduced is formed on one surface of themaster sheet by the transfer of the coating material from the carbonpaper to the master sheet. This mirror reverse copy is attached to thedrum of a spirit duplicator and sheets of copy paper are fed thereto insuccession. Means are provided for moistening the sheets of copy paperimmediately prior to their contact with the master sheet, and since thebasic anilin dyestuif in. the composition on the master sheet is highlysoluble. the moist surface of the copy sheets when consheet cause thetransfer of coloringmatter to the copy sheets. In this process, use maybe made of any desired solvent, but preferably the solvent used isordinarily more volatile than water, the practice having been to makeuse of alcohol, methanol, acetone, or other similar solvents orcombinations of solvents. By the use of such solvents, more copies canbe produced from a single master, and the copies so produced are sharperthan those produced by the use of water. Moreover, the copy so produceddries almost immediately at normal temperature.

, In the practice of all of the foregoing processes, V certain faultsare present which srve to limit the the use of dyestuflwhich is highlywater soluble, it follows that the handling of the dyestuif in mostinstances results in stains both to the person and the clothing of theuser. For example, the

cient to transfer material quantities of the dyestuif to thehands, andconsequently clothing also readily becomes stained, all of which ishighly undesirable. The ribbons, carbons, or fluids which have been usedall contain large quantities I;

.of basic dyestuffs,-such as crystal violet, rho;

damine, Victoria blue, or Victoria green, all of which are water solublecolors. It is evident, therefore, that any process which requires thehandling of ribbons, carbon paper, or ink of this character will producethe objectionable results before set forth.

An object of the present invention is to provide new methods forproducing duplicate copies, which methods are free from theobjectionable results before described.

Another object of the invention is to provide methods of makingduplicate copies, which methods involve the use of transfermaterialwhich in itself and before further treatment possesses substantially noobjectionable color transfer value.

Another object of the invention is to provide methods of producingduplicate copies wherein master copies of the matter being reproducedare formed through the agency of matter having no appreciable colortransfer value and wherein such masters are subsequently treated tocause such material to have high color transfer value.

In carrying out the foregoing and other objects of the invention, thepresent invention contemplates the use of material which in itselfpossesses no appreciable color transfer value and which material is of acharacter as to be insoluble in water. Consequently, this material maybe handled in any manner required by the processes hereinafter describedwithoutincurring the liability of staining the person or clothes of auser.

The basic anilin colors which have previously been used in connectionwith carbon paper and ribbons are in the form of organic salts or estersof highly complicated organic radicals. The present invention makes useof the desirable qualities of these basic'dyestuifs without incurringthe undesirable qualities thereof. To this end, instead of using thebasic colors themselves, use is made of the bases ofsuch basic colorssuch as the bases of crystal violet, methyl violet, rhodamine, Victoriablue, Victoria green, Bismarck brown,

and aurarnine or combinations of these bases.

Bases of these basic dyestuffs can be manufactured in 'any suitablemanner either as an intermediate step in the normal production of thebasic dyestuffs, or as the result of processing basic dyestuffs insolution. For example, when basic dyestuif in solution is treated withdilute alkalies, as for example, sodium carbonate or sodium hydrate, aprecipitate of water insoluble basic color base is formed which is thehydrate of the water Such precipitate may beflltered bearing radical.and dried, and the powder so formed may readily be obtained on themarket as crystal violet base, rhodaminebase, etc.

As a further step in making possible the prac-' tice of the processeswithin the scope of this invention, ribbons or carbons may be made whichincorporate, instead of basic dyestufl', the base of such basic dyestuifwhich is combined with some binding material or vehicle of a characterwhich is substantially free from any acid solvent which user since thematerial which is to be utilized as color transfer material has of'itself no appreciable color transfer value and is water in soluble, butmust be further treated to cause it to acquire high color transfervalue.

Use of the present invention therefore can be made in duplicateprocesses involving the use of gelatin, either in a pan or on a roll. Insuch processes the normal image of the matter to beduplicated, iftypewritten, can be made on a sheet of paper through the agency of aribbon of the character before described. The gelatin, either in the panor on the roll, can be either impregnated or the surface thereof washedwith a dilute acid in aqueous solution; as for example, a ten per centsolution of lactic acid. The acid, either on the surface of the gelatin,or impregnated therein serves to react with the base of the dyestuffabsorbed from the sheet of, paper, having the normal image thereon, toconvert such base of the dyestuif into basic dyestuff. Copies may thenbe'made n the usual manner.

In the adaptation. of the present invention to spirit duplicatingprocesses, again the normal steps followed in such processes are carriedout with the exception that use is made of carbons, or of powdered ink,which have no appreciable transfer value, but which must be subjected,to a reaction to acquire such transfer value. A

" mirror reverse copy of the matter to be duplicated is formed on amaster sheet in any of the usual manners such as for example, by makinguse ,of a coated .carbon containing the base of the dyestuif combinedwith a suitable vehicle. A mirror reverse image of the matter to bereproduced may be activated by a small amount of a relatively weak acidin a number of ways, of which three are hereinafter set forth.

1. An activated sheet specially prepared is made up of a sheet of papercoated with a saturated solution of solid .acid, "such as benzoic, in avolatile solution such as alcohol. To such solution is added an alcoholsoluble gum such as shellac, which diminishes the tendency of the acidto crystallize on the sheet. After the master sheet, having the image inmirror reverse thereon, has been fastened to the drum of the spiritduplicator machine, and prior to the preparation of any copiestherefrom, an activating sheet, or a series of activating sheets, arefed slowly through the machine. The surface of the activating sheet ismoistened by the alcohol or other solvent of the duplicating machine,and' this moistened acid bearing surface is firmly pressed bythe machineagainst the master image, thereby transferring sumcient acid to the baseofthe'dyestuif in the master image as to carry out the proper reactionto convert this base of the dyestuif into basic dyestuih The result ofthis procedure is that the image on the master sheet is now solublesubstantially as if originally made with the objectionable carbonsheretofore employed, and copies may be made in the usual fashion. g

2. The specially prepared activating sheets may be dispensed with and inlieu thereof any acid soluble in or miscible with the solvent used inthe duplicating machine may be added to the solvent in the tank of suchmachine. For this purpose it has been found that the addition of tenpercent of lactic acid causes the solvent in the tank to have sufficientacidity as to carry out the proper reactions.

When such a solution is used in the duplicator tank, the. practice ofmaking copies is followed a the types of duplication 75 in mirrorreverse out as before with these differences in operation. The acidifiedsolution is supplied to the surface of the copy sheet in such minute butsumcient quantity as to provide sumcient acid to react with the-matterof the master image to cause the conversion of limited quantities ofsuch matter into the desiredbasic dyestuff. This conversion, dependingon the quantity of acidified solution supplied to the surface of thecopy sheet, is more or less of local nature, but eventually the entirequantity of material in the master imagewill be converted into theproper dyestufl.

3. In a still further method of performing the necessary chemicalreaction, a master sheet having the image in mirror reverse thereon inwater insoluble dyestufi is prepared as before, but prior to beingattached to the duplicator machine, such sheet is subjected to acidfumes. For example, a closed box may be provided, such box having a feltbottom on which a few drops of acetic acid are placed. A sheet may beintroduced into the box and permitted to remain therein for a suflicientlength of time to permit the acid fumes to accomplish the desiredreaction. In practice it has been found that about five minutes of suchtreatment willsufiice.

The foregoing has been used to describe the present invention in thepreferred form. However, there are other methods which may be utilizedfor securing the water insoluble image on the master copy. One of suchmethods is to substitute an insoluble acid" color for the color basehereinbefore. described and to activate the master by the use of anorganic chemical having a basic reaction, preferably triethynol ammineinstead of the mild acid previously described.

Another method is to convey to the master,

preferably by ribbons or carbons, an image in color material which isinsoluble in water but which is soluble in a particular solvent morevolatile than water. In this event the chemical reaction beforedescribed is not required since the solvent for any spirit duplicationis sumcient to cause the transfer of thecoloring material; and in theevent of the gelatin processes, such solvent can be incorporated in thegelatin. A variety of such dyestuffs are being made and sold by variousdye makers and these dyestuffs particularly are those insoluble in waterbut soluble in alcoholand acetone respectively. These special dyestuffs,

while not preferred in the practice of the present.

invention, may be used with satisfactory results.

As a still further embodiment of the invention that ribbons or carbonsmay it is contemplated be manufactured to contain a material which willreact with another material contained'in either the spirit solvent orthe hectograph gelatin mass to develop color. For example, these stepscan be-followed for obtaining the reaction between gallotannic acid, andiron'salts to produce black coloring material and also the reaction'between ferrocyanide and ferricyanide for the development of bluecoloring matter.

The term "offset duplication processes" in this specification and'in theclaims is'used to'deflne processes described hereinbefore which-have thecommon element that the desired image is produced by dyeing the copylocally as distinguished from lithography (direct or oifset) printing,mimecgraphing, or multigraphing, all of which involve the depodt of apigment on the copy. The term"hectographic process" has also been usedherein to define any process in whiohthe normal image is transferred tothe surface of a gelatin or other suitable compound from which copiesare taken by dyeing the paper locally at such transferred image. Theword hectograp is used to define devices employed in the above describedhectographic process whether such devices be simple pads containing thehectographic composition or machines involving rolls or strips ofsinnartype.

From the foregoing it will be seenthat the present invention providesmethods of producing duplicate copies by ofiset duplication, which'methods overcome the objection heretofore raised thereagainst due to theextreme solubility of the coloring matter which renders the material.

necessarily used in connection with such offset duplication processes,objectionable due to staining of the users person or clothing. It is tobe understood that the invention is capable of modification beyond thoseexamples heretofore set forth and accordingly the limitations to beimposed thereupon are to be such only as are set forth in the followingclaims.

What is claimed is:

1. The method of preparing a master image for use in offset duplicationprocesses which comprises forming a master image of material which initself has no appreciable transfer color value and subsequently reactingsuitable reagent for converting said material into matter having a hightransfer color value.

2. The method of preparing a master sheet for .use in offset duplicatingmachines which comprises. forming a master image with water insolublecolor material and submitting such image to the action of a reagentcapable of making such color material water soluble.

. 3. The method of preparing a master image for hectographic processesWhiChg comprises forming a master image of water insoluble material,transferring .said material to the compound of the hectograph, andreacting with said material while in said compound a reagent capable ofconverting such material into .water soluble matter having hightransferable color value.

-4. The method of preparing a master sheet for hectographic processeswhich comprises forming a master image containing a basic color base andreacting with said base an acid while' said base is incorporated in thehectographic composition.

'5. The method of preparing a master image for use in offset duplicationprocesses which com.- prises forming a master image of water-insolublematerial which in itself has no appreciable transwith said material, a

6. The method of preparing a mirror reverse image for use in spiritduplicators which comprises forming a master image from color materialinsoluble in water, and subjecting the material of said image to areagent to convert such material into water soluble matter.

"-7: The method of preparing a master image for hectographic processeswhich comprises forming a master image of water insoluble material andtransferring the image material to the compound of the hectograph havingassociated therewith a reagent capable of converting such waterinsoluble material to water soluble or transferable color matter.

8. The method of preparing a mirror reverse image for use in spiritduplicators which comprises forming a master image containing basiccolor base insoluble in water, and contacting with said image a reagentcarrying prepared sheet to convert, said basic color base into basiccolor matter.

9. The method of preparing a mirror reverse image for use in spiritduplicating machines which comprises forming a master image with waterinsoluble color material and submitting such image to the action of areagent capable oi. making such color material'water soluble, saidreagent being included in the liquid supply for the machinesand beingsupplied to copy sheets pass-

